login
Number of n X n binary arrays with rows and columns lexicographically nondecreasing and row and column sums nondecreasing.
0

%I #6 Apr 20 2020 19:42:29

%S 2,7,35,276,3669,93085,5061414,654427939

%N Number of n X n binary arrays with rows and columns lexicographically nondecreasing and row and column sums nondecreasing.

%C Diagonal of A266362.

%e Some solutions for n=4

%e ..0..0..1..1....0..0..0..1....0..0..0..1....0..0..0..1....0..0..0..1

%e ..0..0..1..1....0..0..0..1....0..0..0..1....0..0..1..1....0..0..1..0

%e ..0..1..0..1....0..1..1..0....0..0..1..0....0..0..1..1....0..1..0..1

%e ..1..1..1..1....1..1..1..0....1..1..1..0....1..1..0..0....0..1..1..1

%Y Cf. A266362.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 28 2015